DE 697 09 291 T2 (EP 0 840 087 B1) discloses means for controlling the initial velocity of a projectile. In this case, a sensor means is provided which can measure a parameter that is related to the muzzle velocity. This is done with the aid of the sensors, which are fitted at least in or on the weapon barrel and can record a higher pressure in the weapon barrel, which is caused by the heating of the propellant gases on the weapon barrel. Strain gauges are proposed as sensors, and are adapted such that they make contact with the weapon barrel. In this case, the expansion of the weapon barrel is measured. The movement and therefore the velocity of the projectile are determined by the two individual sensors from the time difference between registration of the projectile passage.
DE 10 2005 024 179 A1 dispenses entirely with direct measurement of the current muzzle velocity, since the actual muzzle velocity is determined by information relating to the current airspeed of the projectile, that is to say is calculated back from this. This current projectile velocity is then used to correct the detonation time of the projectile with the aid of a detonation time preset using a standard muzzle velocity, and this is used as the current fuze setting time. A microwave transmitter, preferably in the GHz range, is used to transmit this information to the projectile and sends the current temperature, determined for example by a fire control computer, to the munition or to a projectile.
A further method is to operate the tube as a round waveguide and to measure the Doppler velocity of the projectile in the barrel, as disclosed in EP 0 023 365 A2. In this case, the frequency of the signal is above the cut-off frequency for the relevant waveguide mode. The electromagnetic wave which is formed in this case propagates in the barrel and is reflected from the projectile. A Doppler frequency shift also occurs, as a function of the instantaneous velocity.
DE 10 2006 058 375.2, which was not published prior to this, proposes that the weapon barrel or the firing barrel and/or parts of the muzzle brake be used as a waveguide (a waveguide is a tube with a characteristic cross-sectional shape which has a very highly electrically conductive wall, in particular, rectangular and round waveguides are in widespread use for technical purposes), which, however, is operated below the cut-off frequency of the relevant waveguide mode.